Is there a way to modify Input Manager so that an ax is be able simulate an input from code?

Hello, I am asking if there is a way to simulate an ax from code. What I mean is that a class is something like this:

public class Capsule : MonoBehaviour {
private void Update()
{
if (Input.GetAxisRaw("Horizontal")>0)
{
//do something
}
}
}
I want to enter the if statement without pressing anything only via code. Is there a way without modifying the code?